1. Field of the Invention
The present invention relates to a wire bonding apparatus used for, for example, semiconductor manufacturing.
2. Prior Art
In conventional wire bonding apparatuses, a bonding arm is attached to a bonding head (which is driven in the X and Y directions by an XY table) either directly or via a lifter arm. The bonding arm can move upward and downward or swing, and a capillary through which a bonding wire is passed is attached to the front end of the bonding arm. A vibrator that transmits a vibration to the bonding arm is mounted to the rear end of the bonding arm or on the bonding head side. When the wire or a ball formed at the tip end of the wire is bonded to a workpiece, the vibrator and the bonding arm are caused to resonate at an appropriate resonance frequency.
In this prior art, the attachment of the bonding arm to the bonding head or the lifter arm is limited to the node (vibrational node) of the bonding arm. In addition, there are restrictions on the shape, length, etc., of the bonding arm when obtaining a desired resonance. Thus, there are problems in terms of design and quality control. Moreover, since the vibration of the vibrator is transmitted from the rear side of the bonding arm to the capillary which is at the front end of the bonding arm, the conversion efficiency of the vibrational energy is poor. In addition, since the resonance frequency shifts due to fluctuations in the load when bonding is performed, a frequency tracking circuit must be installed to track the resonance frequency.